/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * -------------
 * TickUnit.java
 * -------------
 * (C) Copyright 2001-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 19-Dec-2001 : Added standard header (DG);
 * 01-May-2002 : Changed the unit size from Number to double (DG);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 05-Sep-2005 : Implemented hashCode(), thanks to Thomas Morgner (DG);
 * 02-Aug-2007 : Added minorTickCount attribute (DG);
 *
 */

package net.droidsolutions.droidcharts.core.axis;

import java.io.Serializable;

/**
 * Base class representing a tick unit. This determines the spacing of the tick
 * marks on an axis.
 * <P>
 * This class (and any subclasses) should be immutable, the reason being that
 * ORDERED collections of tick units are maintained and if one instance can be
 * changed, it may destroy the order of the collection that it belongs to. In
 * addition, if the implementations are immutable, they can belong to multiple
 * collections.
 * 
 * @see ValueAxis
 */
public abstract class TickUnit implements Comparable, Serializable {

	/** For serialization. */
	private static final long serialVersionUID = 510179855057013974L;

	/** The size of the tick unit. */
	private double size;

	/**
	 * The number of minor ticks.
	 * 
	 * @since 1.0.7
	 */
	private int minorTickCount;

	/**
	 * Constructs a new tick unit.
	 * 
	 * @param size
	 *            the tick unit size.
	 */
	public TickUnit(double size) {
		this.size = size;
	}

	/**
	 * Constructs a new tick unit.
	 * 
	 * @param size
	 *            the tick unit size.
	 * @param minorTickCount
	 *            the minor tick count.
	 * 
	 * @since 1.0.7
	 */
	public TickUnit(double size, int minorTickCount) {
		this.size = size;
		this.minorTickCount = minorTickCount;
	}

	/**
	 * Returns the size of the tick unit.
	 * 
	 * @return The size of the tick unit.
	 */
	public double getSize() {
		return this.size;
	}

	/**
	 * Returns the minor tick count.
	 * 
	 * @return The minor tick count.
	 * 
	 * @since 1.0.7
	 */
	public int getMinorTickCount() {
		return this.minorTickCount;
	}

	/**
	 * Converts the supplied value to a string.
	 * <P>
	 * Subclasses may implement special formatting by overriding this method.
	 * 
	 * @param value
	 *            the data value.
	 * 
	 * @return Value as string.
	 */
	public String valueToString(double value) {
		return String.valueOf(value);
	}

	/**
	 * Compares this tick unit to an arbitrary object.
	 * 
	 * @param object
	 *            the object to compare against.
	 * 
	 * @return <code>1</code> if the size of the other object is less than this,
	 *         <code>0</code> if both have the same size and <code>-1</code>
	 *         this size is less than the others.
	 */
	public int compareTo(Object object) {

		if (object instanceof TickUnit) {
			TickUnit other = (TickUnit) object;
			if (this.size > other.getSize()) {
				return 1;
			} else if (this.size < other.getSize()) {
				return -1;
			} else {
				return 0;
			}
		} else {
			return -1;
		}

	}

	/**
	 * Tests this unit for equality with another object.
	 * 
	 * @param obj
	 *            the object.
	 * 
	 * @return <code>true</code> or <code>false</code>.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof TickUnit)) {
			return false;
		}
		TickUnit that = (TickUnit) obj;
		if (this.size != that.size) {
			return false;
		}
		if (this.minorTickCount != that.minorTickCount) {
			return false;
		}
		return true;
	}

	/**
	 * Returns a hash code for this instance.
	 * 
	 * @return A hash code.
	 */
	public int hashCode() {
		long temp = this.size != +0.0d ? Double.doubleToLongBits(this.size)
				: 0L;
		return (int) (temp ^ (temp >>> 32));
	}

}
